Who said substance was unsexy?

After six months, news aggregator Upworthy has proven that viral videos work as a conduit for politically-relevant information just as well as, say, cats or Carly Rae Jepsen. The Chris Hughes-backed site, which describes itself as “social media with a mission,” picked up an impressive six million uniques in September according to Google Analytics, up from just over 4 million in August.

To help catapult that growth, the company has raised $4 million from the venture capital firm NEA, as well as a host of familiar angel investors, including Reddit cofounder Alexis Ohanian and BuzzFeed cofounder John Johnson. Mr. Hughes, who is also fighting the good fight as owner of the The New Republic,reupped, participating in this round as well, the company confirmed. The pedigree of the site’s cofounders reflect Upworthy’s tone: Eli Pariser is the former executive director of MoveOn and Peter Koechley is former managing editor of The Onion.

Impressively, most of the growth has been organic. In a press release, the company said, “After just about 6 months in business, our core audience has grown to a community of more than 425,000 Facebook fans and more than 265,000 daily email subscribers. We’re now branching out into other social networks, garnering more than 33,000 Twitter followers and 7,000 Tumblr followers in the last few weeks.”